Manufacture of rivets



Filed Oct. 7. 1929 I INVENTOR 4 MARION M. CUNNlNGHAM BY J;

A ORNEY Patented Sept. 6, 19 32 UNITED STATES PATENT OFFICE- MARION M.CUNNINGHAM, OF SOUTH BEND, INDIANA, AssI oNon T0 BENDIX BRAKE COMPANY,OF SOUTH BEND, IND ANA, A CORPORATION OF ILLINOIS MANUrAcIUnE ou RIVETSI Application-filed October 7, 1929. Serial No. 397,795.

This invention relates to the manufacture of rivets and is illustratedas embodied in the apparatus for forming a novel type of rivet adaptedfor use in securing the friction lining to the brake shoe of anautomobile brake.

The invention is particularly designed to produce, in an expeditiousmanner, a very simple form of rivet shaped at one of its ends toaccommodate a plug member. In one preferred embodiment of my novelprocess relatively thick tubular stock is fed vertically through arotatable guide member, the stock being protruded through openings in arotatable indexed die or support plate toward a rotating shaping tool inaxial alignment with the stock and preferably but not necessarily movingtoward the same and adapted to spread the outer end of the stock to forma cup-shaped recess in the end of the rivet. The stock is then severedto complete the rivet and subsequently filled with the aforementionedinsert to complete the rivet assembly.

According to another feature of my invention, a molded type of brakefriction material is provided with openings of predetermined bore toreceive the rivets effected by my aforementioned novel process, andwhich rivets are extended through openings in a brake shoe rim andsubsequently upset on the inner face thereof to firmly secure the liningto the shoe.

Other features of my invention, including novel steps in forming theproduct, details of construction and combinations of parts will variousdies and their relative position in one step of the forming operation.

As disclosed in Figure 3 of the drawing, one

form of, apparatus for efiecting my novel rivet includes an" indexedrotatable lo-wer die mem ber 10 provided with a plurality of annularlyspaced two-diametered recesses 12, the first of these "openings has inaxial alignment therewith a rotatable tubular guide member 14 adapted toreceive relatively thick copper, brass or other copper alloyed stockfrom which the rivetsv may be fabricated. The tubular stock is feddownwardly through the rotating guide 14 protruding through the smallerbore of the recesses 12 and at the same time a lower forming or spinningtool 16 rotating in opposite direction to the direction of rotation ofthe guide member 14 is movedupwardly in axial alignment with the stock,said tool being provided with'a cylindrical pro jection 18 whichtelescopes within the endof the stock. Fillets 20 and 22 of the tool anddie'plate serve to shape the end of thestock into the cup shapestructure disclosed in Figure 4, the movement ofthe stock and shapingtool being synchronizedto be stopped when the end of the projection 18reachesthe bottom of the die plate. The forming tool is then withdrawnand the rivet cut to length by a laterally movable cutting tool 24 asdisclosed in Figures 3 and 4. 1 v A The die plate 10 is then rotated toposition the rivet beneath a ram member 26 (Figure 3) cupped inits endand loaded with a graphite, lead or other suitable. cylindrical frictionfiller orplugr member 28. The ram 26 is then moved upwardly, forcingthe-filler orplug into the cupped recess formed in the end of the rivetwhereupon the ram is withdrawn. The die plate is then rotated toposition indicated in Figure 8; and the rivetis then'knocked outofjtheopening into a hopper (not shown) by suitable mechanism 30.

According to a second phase of my invention, the rivets so formed may beadaptedto secure the friction lining of a. brake shoe to the rim ,"fac'ethereof and my rivet finds par: ticular utility in securing themolded-type of friction lining in place. VVith thistype V of lining itis quite necessary that the secur ing means, such as the rivets, snuglylit the openings in the lining. The molded lining, preformed inmanufacture, is accordingly drilled and counterbored to provide openingscorresponding in diameter to the two diameters of my novel rivet. Thelining is then placed upon the rim face 82 of the brake shoe 34:disclosed in Figure 1 and the rivets formed by my novel process insertedwithin substantially coaxial openings in the lining and rim face.

, Theends of the rivets may then be upset upon the inner face of therim, as clearly disclosed in Figures 1 and 2, the upsetting of therivets serving to force the shank portion of the same passing throughthe body of the lining and rim into close contact'with the walls of theopenings therein. I also suggest that the lining be recessed to a depthso 'that the surface of the plugs 28 in the rivet are flush with thesurface of the lining-all as indicated in Figure 1. A very secureattachment of the molded lining to the steel rim face is thus'effected,inasmuch as the cup-shaped portion of the rivet and its shank portionclosely nest within the openings in the friction lining, the remainderof the shank portion being securely affixed to the body of the rim withthe upsetting. The tight fit of the rivets in the lining and rimprecludes relative movement of these parts and the ultimate result isthat this type of lining is very securely attached to the face of abrake shoe.

While one illustrative embodiment has been described in detail, it isnot my intention to limit the scope'of the invention to that particularembodiment or otherwise than by the terms of the appended claims. Partof the subj ec't-matter herein disclosed is covered by my divisionalapplication No. 599,290, filed March 16, 1932.

I claim:

1. That method of forming rivets which comprises feeding and rotatingtubular stock against an axially moving shaping tool to tating inopposite direction to the direction of rotation of the stock to providea cup at one end of the stock to form a rivet head,

4. That method of forming rivets comprising axially feeding rotatingtubular stock and moving toward the same, said tool having a parttelescoping-within the bore of the stock and otherwise constructed toeffect a cup shape to one end of the stock and subsequently severingsaid stock below said cup and filling said cup with a plug to completethe rivet.

In testimony whereof, I have hereunto signed my name.

MARION M. CUNNINGHAM.

severing the headed portion of the stock, and

of rotation of the stock'to provide a cup at one end of the stock toform a rivet head and subsequently cutting said stock to provide a shortshank portion for the rivet.

3. That method of forming rivets which comprises feeding and rotatingstock into engagement with a rotating spinning tool rotating in oppositedirection to the direction of rotation of the stock and telescopingwithin the stock to form a cup at one end of the stock to form a rivethead of larger diameter than the bore of the stock, and severing fromthe stock the end portion so formed with a cup-shaped head. i i

